Cloth ring seal

ABSTRACT

A seal assembly including a low flow cloth ring seal having a cloth assemblage is provided for sealing a tubular cavity disposed between a tubular member and a mating body. The density of the cloth assemblage may be set according to a desired flow rate of gas through the cloth ring seal. In applications where more stiffness and strength is desired, the cloth ring seal may include a shim assemblage surrounded by the cloth assemblage.

FIELD OF THE INVENTION

The present invention is directed to seals for dynamic or rotatingapplications. More particularly, the present invention relates to acloth ring seal for dynamic and rotating applications.

BACKGROUND OF THE INVENTION

Seals can be used to minimize leakage of fluids including gas inapplications where two relative movable mechanical members are in closeproximity. The members may have substantial relative motion between oneanother, such as a turbine shaft against lubricating oil reservoir, or arotatable turbine stage relative to a fixed support structure having towithstand a pressure differential across the stage. Also, the movementbetween members may be caused by vibration or thermal growth.

Leakage of gas and air can negatively impact performance of componentsin many systems including a gas turbine combustion system. Matingcomponents may be formed of different materials and can be subjected todifferent temperatures during operation. Consequently, the componentscommonly experience varying degrees of thermal growth. For example, afuel nozzle burner tube and a combustion liner cap assembly supportstructure in a gas turbine move radially, axially, and circumferentiallyrelative to one another based on thermal growth. Similar relativemovement may also occur due to dynamic pulsing of the combustionprocess. To prevent leakage and compensate for the relative movement ofthe fuel nozzle burner tube, a split ring metal seal has been placedaround the outer diameter of the fuel nozzle burner tube providing aninterface between the burner tube and a portion the cap assembly supportstructure.

Rather than an airtight seal, a certain amount of leakage between thefuel nozzle burner tube and the cap assembly support structure isdesired. In this regard, hot gases from the combustion reaction zonetend to “backflow” into a tubular cavity between the fuel nozzle burnertube and the cap assembly support structure components. When the hotgases flow into the tubular cavity, they can damage the hardware, whichsignificantly shortens the usable life of the components. To preventbackflow, a certain amount of air leakage needs to be permitted to flowthrough the seal. In an attempt to address this concern, theconventional split ring metal seal has slots cut through the seal toallow some leakage of air.

Several problems exist with the split ring metal seal. Since the seal ismetal and the interfacing components are metal, the components and sealtend to rub, vibrate or otherwise move against one another causingexcessive wear of the seal and the components. Further, the burner tubeand cap assembly support structure components and the seal generally donot perfectly fit together due to slight physical discrepanciesresulting from manufacture. Stated differently, each component ismanufactured to a particular tolerance, and is not perfectly shaped dueto real world limitations. In addition, over time the components andseal will tend to change shape due to thermal distortion and physicalwear. As a result, the amount of leakage of air around the burner tubecannot be effectively controlled and tends to be non-uniform, varyingfrom one location to another.

In the past, a substantial number of seals have been employed in turbinesystems. Labyrinth seals have been employed between rotating matingsurfaces or vibrating mating surfaces. However, labyrinth seals do noteasily conform to vibratory movement or rotating surfaces, particularlywhen the surfaces have imperfections. Consequently, labyrinth seals havenot proven particularly effective.

Brush seals have been used in many environments including in gas andsteam turbines. Brush seals generally conform better to rotating and/orvibrating mating surfaces than labyrinth seals including surfaces havingimperfections. While brush seals have proven more effective thanlabyrinth seals, they are exceedingly expensive to manufacture anddifficult to handle. For example, the very fine bristle wires of a brushseal are not bound together prior to assembly. As a result, it is anarduous process to lay out a predetermined layer of bristles to therequired thickness to form a bristle pack suitable to form the resultingseal. Consequently, there is a need to provide a less expensivemechanism for providing a low leakage seal which is sufficientlyresilient to accommodate the dimensional changes in the radial, axial,and circumferential directions resulting from wear and thermal growth.Also, there is a need for a seal that can regulate the amount of leakagethere through.

BRIEF SUMMARY OF THE INVENTION

The present invention overcomes many of the shortcomings of prior artseals. According to an illustrative implementation of the presentinvention, a cloth ring seal interfaces two mating bodies in order toprovide a low leakage cloth seal.

In one aspect of the invention, a low leakage cloth ring seal isprovided where, based on the conditions through the interface, the clothseal may be designed to include an area where fluids including gas canflow through at least portion of the cloth assemblage of the cloth ringseal. Knowing the flow conditions and the pressure differential throughthe interface, the density of the cloth ring seal including thicknessand number of cloth layers may be designed to allow for a desiredleakage amount or flow rate. In another aspect of the invention, gasflowing through the seal can be used to purge a cavity of unwanted gasesand/or cool the cavity or surfaces of the mating bodies providing thecavity boundaries.

According to an aspect of the invention, a cloth ring seal is adapted toseal a tubular cavity between a first mating body and a second matingbody, where the cloth ring seal has an inner circumferential portion formaking sealing contact with the second mating body. In another aspect ofthe invention, the cloth ring seal includes a tubular cloth assemblageforming the periphery of the cloth ring seal, where a portion of theperiphery of the cloth assemblage makes sealing contact with the secondmating body. In still another aspect of the invention, a cloth ring sealmay further include a shim assemblage surrounded by the clothassemblage. The cloth assemblage and the shim assemblage may be tubular.

In another aspect of the invention, a high temperature, woven cloth ringseal can be provided in a tubular cavity between a burner tube of a fuelnozzle and a cap assembly to act as an interface. In another aspect ofthe invention, leakage through the woven cloth seal can be controlled topurge a tubular cavity separating the burner tube and cap assembly ofunwanted hot gases.

These and other novel advantages, details, embodiments, features andaspect of the present invention will be apparent to those skilled in theart from following the detailed description of the invention, theattached claims and accompanying drawings, listed herein, which areuseful in explaining the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of an illustrative fuel nozzle andmanifold assembly in a gas turbine.

FIG. 2 shows an exploded view of an illustrative cap assembly to whichplural fuel nozzles can be interfaced in a gas turbine.

FIG. 3 shows a perspective view taken from a combustion zone of anillustrative cap assembly interfacing with a plurality of fuel nozzlesin a gas turbine according to an exemplary embodiment of the presentinvention.

FIG. 4 shows a partial cross section of the interface region between thecap assembly and fuel nozzle according to an exemplary embodiment of thepresent invention.

FIG. 5 shows a cross-sectional view of an illustrative cloth sealconfiguration according to a first exemplary embodiment of the presentinvention.

FIG. 6 shows a cross-sectional view of an illustrative cloth sealconfiguration according to a second exemplary embodiment of the presentinvention.

FIG. 7 shows a cross-sectional view of an illustrative cloth sealconfiguration according to a third exemplary embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-4, an exemplary gas turbine environment in whichthe present invention may be implemented is shown. In gas turbines,plural combustors are disposed in an annular array around the axis ofthe machine. As shown in FIG. 1, each combustor includes plural fuelnozzles 20, which are attached to a fuel manifold plate 10 called anendcover. The number of fuel nozzles 20 may vary depending on desiredperformance (e.g., FIG. 3 shows five fuel nozzles and FIG. 1 shows fourfuel nozzles). Each fuel nozzle 20 has many components including theburner tube 25, which is to the remainder of the fuel nozzle 20 by, forexample, a weld 28. Also, each fuel nozzle 20 has a diffusion gas tip30. The fuel nozzles 20 penetrate through a structure called a capassembly 40, which provides the boundary between compressor air used forthe combustion process and a combustion burning zone. A burner tube 25of each fuel nozzle 20 engages the cap assembly 40 through an interface(not shown in FIGS. 1-3). The interface is located in a tubular cavity50 between the burner tube 25 and the cap assembly 40. The fuel nozzle20 allows gas and air to premix in the premixer zone 52 of the burnertube 20 prior to the actual combustion in the combustion burning zone or“reaction zone”. The combustion burning zone is directly downstream fromthe diffusion gas tip 30 of the burner tube 25. Premixing of gas and airprior to combustion allows a more uniform fuel/air mixture and isimportant in minimizing emissions in gas turbines.

Referring to the exploded view of the cap assembly 40 depicted in FIG.2, the cap assembly 40 includes inner body assembly 42, outer bodyassembly 44 and outer barrel assembly 48. The outer barrel assembly 48is shown with the outer body assembly 44 coupled thereto and the innerbody assembly 42 coupled to the outer body assembly 44. Four fuelnozzles 20 engage with the cap assembly 40 in the four tubular holes inthe outer body assembly 44. In an illustrative embodiment of the presentinvention, the locations 46 represent exemplary portions of the capassembly 40 where a seal can interface with the burner tube of the fuelnozzle. Air can flow through holes 45 (in FIG. 2) and eventually intothe tubular cavity 50 between the cap assembly 40 and the burner tube 25as shown in FIG. 3. FIG. 4 depicts a partial cross section of the capassembly 40 with the burner tube 25 engaged therein. As shown, a sealassembly 60 including the cloth seal is placed in the tubular cavity 50between the burner tube 25 and the cap assembly 40. A seal retainer 55couples the seal assembly 60 to the cap assembly 40. The seal retainer55 may be permanently fixed to and part of the cap assembly 40.

FIGS. 5-7 illustrate exemplary cloth ring seal configurations that maybe employed as the interface between burner tube 25 and cap assembly 40shown in FIG. 4. It should be understood that the cloth sealconfigurations in FIGS. 5-7 may be used as low leakage seals for bothstatic applications, such as around nozzles or tubes, and dynamicapplications, such as around rotating components in, but not restrictedto, gas or steam turbine environments.

The embodiments of FIGS. 5-7 illustrate a cloth ring seal 65 extendingfrom a first mating body 70 through a tubular cavity 75 between thefirst mating body 70 and a second mating body 80 and making sealingcontact with the second mating body 80. The cloth ring seal 65 has aninner circumferential portion which makes sealing contact with thesecond mating body 80. In a preferred implementation of each embodiment,the second mating body is a tubular member such as a nozzle. It shouldbe understood that the second mating body 80 could be a static orrotating component. The cloth ring seal 65 has a cloth assemblage 62,which as shown in the illustrative embodiments of FIGS. 5 and 6 forexample, can be used to define the outer periphery of the cloth ringseal 62. As shown in FIGS. 5-7, an outer periphery of the clothassemblage 62 can comprise the inner circumferential portion of thecloth ring seal 65 which extends into the tubular cavity 75 and makessealing contact with the second mating body 80. The cloth assemblage 62can surround a cavity in a central portion of the cloth ring seal 65.The cavity can be a tubular void.

The cloth ring seal 65 can be sandwiched between metal plates (notshown) or otherwise coupled to another portion of the seal assembly. Theseal assembly is physically attached to the first mating body 70.

In contrast to the exemplary embodiment of FIG. 5, FIG. 6 furtherincludes a shim assemblage 64 such as a sheet metal tube enclosed by alayer of cloth of the cloth assemblage 62. The outer periphery of theshim assemblage 64 may oppose the inner periphery of the clothassemblage 62. The inner periphery of the shim assemblage 64 may opposethe periphery of the cavity with the shim assemblage 64 surrounding orenclosing the cavity (e.g., tubular void). Each of the cloth assemblage62 and the shim assemblage 64 may be tubular.

The cloth ring seal 65 of FIG. 7, while providing sealing functionalityequivalent to the cloth ring seal 65 of FIG. 6, illustrates a structuralmanufacturing alternative to the embodiment of FIG. 6. The cloth ringseal 65 of FIG. 7 has a cloth assemblage 62 including planar clothstrips 66A and 66B which may be stitched together and an arcuate clothportion 66C. The arcuate cloth portion 66C has a first end coupled(e.g., stitched) to a planar cloth strip 66B and a second end coupled(e.g., stitched) to a planar cloth strip 66A. The arcuate cloth portion66C and the planar cloth strips 66A, 66B form a closed loop.

Also, the cloth ring seal 65 of FIG. 7 further includes a shimassemblage 64 with an outer peripheral portion opposing an innerperipheral portion of the cloth assemblage 62. The shim assemblage 64includes two planar shim strips 68A, 68B welded together and an arcuateshim portion 68C. The arcuate shim portion 68C has a first end coupled(e.g., welded) to a planar shim strip 68B and a second end coupled(e.g., welded) to a planar shim strip 68A. The arcuate shim portion 68Cand the planar shims strips 68A, 68B form a closed loop.

A joining member 72 as shown in FIG. 7 can couple the arcuate clothportion 66C to planar cloth strip 66A. Also, the joining member 72 cancouple the arcuate shim portion 68C to planar shim strip 68A. In theembodiment of FIG. 7, the joining member 72 couples the cloth assemblage62 to the shim assemblage 64 and in particular couples together arcuatecloth shim portion 68C, arcuate cloth portion 66C, planar shim strip 68Aand planar cloth strip 66A. The joining member 72 may be a slotted tabor other fastening device. While two planar cloth strips are shown inFIG. 7, multiple planar cloth strips may be connected together by beingstitched together as necessary for ease of manufacturing.

The cloth assemblage in the embodiment of FIG. 5 and the cloth-shimassemblages in the embodiments of FIGS. 6 and 7 are designed to permitleakage of fluids (e.g., gas such as air) through the seal. It should beunderstood that leakage according to embodiments of the invention willbe described below in terms of gas leakage, and that such description ismerely illustrative and that the present invention may be applied toleakage of fluids other than gas.

In the embodiments of the present invention depicted in FIGS. 5-7,leakage occurs at least through the cloth assemblage 62 portion of thecloth seal 65 between the inner circumferential portion of the shimassemblage 64 located closest to the mating body 80 and the innercircumferential portion of the cloth seal 65 contacting the secondmating body 80. The cloth assemblage 62 is porous, and can provide somecontrolled leakage to provide airflow such as cooling air to downstreamlocations. In FIGS. 5-7, the arrows show the airflow direction. For thecross-sections shown FIGS. 5-7, airflow is from the left region of thecavity 75 through the cloth ring seal 65 to the right region of thecavity 75. In FIG. 5, the cloth seal 65 does not include a shimassemblage. The cloth seal 65 of FIG. 5 may be utilized in applicationswhere high flow rates are desired, such as for cooling.

According to embodiments of the invention, the cloth assemblage 62 ofthe cloth seal 65 is flexible and includes at least one layer of cloth.Alternatively, the cloth layer may include two overlying layers ofcloth. Each cloth layer may include metal, ceramic and/or polymer fibersthat have been woven, knitted or pressed into a layer of fabric. Eachcloth layer provides sacrificial wear volume and wear resistance withouta significant increase in stiffness to the seal. Cloth layers, due totheir porosity, are more resilient than metal layers. Thus, cloth sealscan more readily adapt to the changing size and shape of mating bodiescaused by thermal distortion, vibration and other relative movement,thereby providing an effective seal. In embodiments such as FIGS. 6 and7, the cloth assemblage 62 can reduce heat conducted to the shimassemblage 64, thereby lessening structural degradation to the matingbodies 70, 80 caused by friction, for example when metal rubs againstmetal.

Choices as to the construction of the cloth layer (e.g., woven, knittedor pressed), the material(s) selected for the cloth layer, and thethickness of the cloth layer can be made by one skilled in the art whendesiring to tune or calibrate the seal based on the wear resistance,flexibility and sealing requirements associated with the particular sealapplication. Multiple cloth layers can include different materials,different layer construction (e.g., woven, knitted or pressed), and/orhave different thicknesses or densities depending on the sealapplication. In turbine applications, the cloth layer is preferablywoven (e.g., using a Dutch Twill weave). An exemplary cloth assemblageused in turbine applications employs a Dutch Twill woven cloth layer,the cloth layer being made of a high-temperature Cobalt-basedsuper-alloy such as L-605 or Haynes-25. Other low stiffness and lowfriction abradable cloth layers can be used depending on theapplication. For example, Teflon may be used as a cloth layer for lowtemperature applications.

The shim assemblage 64 of the cloth seals in FIGS. 6 and 7 can beflexible, resilient, generally imperforate, and generally impervious togas. The shim assemblage 64 can provide blockage for through clothleakage, structural stiffness to withstand pressure loads, andresiliency necessary for recovery following interference/excursion,i.e., displacement from a free state. The resilient quality of the shimassemblage 64 maintains the sealing properties of the cloth seal whileallowing for different surface shapes, assembly misalignment, vibrationand/or thermally-induced relative movement between the first mating body70 and the second mating body 80. Thus, the flexible shim assemblage 64serves as a structural member carrying the pressure loads whileproviding some resiliency, which allows the cloth seal to recover afterinterference or excursion.

The shim assemblage 64 comprises at least one shim (thin metal layer)layer, but may comprise two or more superimposed shim layers forincreased strength. For turbine applications, the shim assemblagepreferably contains four or fewer shim layers. The shim assemblage 64may have sliced and/or staggered pieces of sheet metal spot-weldedtogether to add flexibility, while maintaining strength, and/or to helpthe seal conform to the curvature of surfaces of the mating bodies. Thechoices of materials for the shim assemblage and the thickness of eachlayer of shim can be made by one skilled in the art to tune or calibratethe seal in accordance with sealing, flexibility and resiliency needs ofthe particular seal application. Each shim layer includes a metal,ceramic and/or polymer sheet. For turbine applications, the shimassemblage generally has a thickness between {fraction (1/100)} and ⅕ ofan inch and each shim layer includes a high temperature, cobalt basedsuper-alloy, such as Inco-750 or HS-188.

Applying the cloth seal to the gas turbine application shown in FIGS.1-4, the first mating body corresponds to the cap assembly 40 includingthe seal retainer 55 which is fixedly attached thereto, the secondmating body corresponds to the fuel nozzle 20, and more particularlyburner tube 25, and the cavity 75 corresponds to the tubular cavity 50.In this application, the air flows from the internal side of the capassembly (i.e., high pressure side) to the side opening into thecombustion zone (i.e., low pressure side).

Referring to FIGS. 3 and 4, a fuel/air premixture exits a premixer zone52 between the burner tube 25 and diffusion gas tip 30 and enters thecombustion burning zone in a swirling manner. Due to the pressuregradients caused by the swirling mixture, some of the hot gases tend toback flow into the tubular cavity 50. The backflow of hot gases into thetubular cavity 50 can damage the hardware including the burner tube 25and cap assembly 40. To prevent this problem and to purge the tubularcavity of hot gases, a cloth seal according to exemplary embodiments ofthe present invention shown in FIGS. 5-7 can be used as an interfacebetween the burner tube 25 and cap assembly 40. The exemplary cloth ringseals according to the invention, allow air in the tubular cavity 50 toflow through the seal from the high pressure side to the low pressureside (e.g., from left to right in the cross-sectional view shown inFIGS. 5-7) forcing the hot gas backflow out of the tubular cavity 50.

The resiliency of cloth seals allows for the accommodation of anynon-uniformity in the seal interface (e.g., warping, thermal distortion)in the design of the cloth seal. Also, illustrative low leakage clothseals according to the invention can be designed to control the leakagepassing through the seal by selecting the cloth seal density (e.g.,effective flow area through the cloth seal assemblage 62 in FIGS. 5-7when the shim assemblage 64 is impervious) taking into account thepressure drop through the seal interface. That is, knowing the flowconditions (i.e., pressure and temperature) and the pressure dropbetween the high pressure region and low pressure region, the sealdensity (effective flow rate through the seal) can be set to a desiredleakage flow rate. In setting the desired leakage, the followingrelationship can be employed for incompressible flow:

W=A_(eff)·{square root over ((2g_(c)/RT_(H))·P_(H)·(P_(H−P) _(L)))}

where A_(eff)=effective area of seal; g_(c)=gravitational constant;R=gas constant for air; P_(H)=upstream pressure—high pressure regionpressure; P_(L)=downstream pressure—low pressure region pressure;T_(H)=high pressure region temperature and W=leakage. Embodiments of thepresent invention regulate fluid flow and provide uniform distributionof leakage around the cloth ring seal. By providing uniform distributionof leakage, “lean” regions and “rich” regions of leakage can be avoided,thereby increasing efficiency.

While the above example of the present invention involves a sealinginterface between a cap assembly and burner tube portion of fuel nozzlein a gas turbine system, it should be understood that the presentinvention can apply to many other gas and steam turbine applications aswell as other sealing applications. For example, embodiments of thecloth seal of the present invention include any application, whetherbetween flat surfaces, around static or rotating tubular members orotherwise, in which flow rate control can be applied. In this regard,the cloth seal according to the invention may be a fully circular ringor it may be in tubular segments as called for in the particularapplication. In certain sealing applications, the cloth ring seal may beplaced in a circumferential geometric opening(s) between mating bodies.A cloth seal according to illustrative embodiments of the invention canbe used in the form of linear strips in applications where relativemotion exists between two flat surfaces. Also, according to embodimentsof the invention, a cloth ring seal may be used in series with otherseals, such as cloth ring seals, brush seal and labyrinth seals, to sealtwo mating bodies.

While particular embodiments of the present invention have beendescribed and illustrated, it should be understood that the invention isnot limited thereto since modifications may be made by persons skilledin the art. The present application contemplates any and allmodifications that fall within the spirit and scope of the underlyinginvention disclosed and claimed herein.

What is claimed is:
 1. A seal assembly comprising: a cloth ring sealadapted to seal a tubular cavity between a first mating body and asecond mating body, said cloth ring seal having an inner circumferentialportion adapted to make sealing contact with the second mating body;wherein said cloth ring seal includes a cloth assemblage, the innercircumferential portion of said cloth ring seal adapted to make sealingcontact with the second mating body including an outer peripheralportion of said cloth assemblage; wherein said cloth ring seal furtherincludes a shim assemblage with an outer peripheral portion opposing aninner peripheral portion of said cloth assemblage, said shim assemblageincluding a plurality of planar shim strips welded together and anarcuate shim portion, said arcuate shim portion having a first endwelded to a first planar shim strip and a second end coupled to a secondplanar shim strip, wherein said arcuate shim portion and said planarshims strips form a closed loop.
 2. The seal assembly according to claim1, wherein said second mating body comprises a portion of a fuel nozzle.3. The seal assembly according to claim 1 wherein a density of saidcloth ring seal is selected to control the rate of flow of a gas throughsaid cloth ring seal.
 4. The seal assembly according to claim 1, whereinsaid cloth ring seal includes an annular cavity disposed therein.
 5. Theseal assembly according to claim 4 wherein said shim assemblage isinterposed between said annular cavity and said cloth assemblage.
 6. Theseal assembly according to claim 1, wherein said cloth assemblage andsaid shim assemblage are tubular.
 7. The seal assembly according toclaim 1 wherein said cloth assemblage includes a plurality of planarcloth strips coupled together.
 8. The seal assembly according to claim1, wherein said cloth assemblage is adapted to permit a flow of fluidthrough said cloth ring seal from a first region of said tubular cavityto a second region of said tubular cavity.
 9. The seal assemblyaccording to claim 8, wherein said fluid comprises a gas.
 10. The sealassembly according to claim 1, wherein said first mating body comprisesa cap assembly and second mating body comprises a fuel nozzle of a gasturbine engine.
 11. The seal assembly according to claim 1, wherein saidsecond mating body is rotatable within the cloth ring seal.
 12. A sealassembly comprising: a cloth ring seal adapted to seal a tubular cavitybetween a first mating body and a second mating body, said cloth ringseal having an inner circumferential portion adapted to make sealingcontact with the second mating body, said cloth ring seal furtherincluding a cloth assemblage; wherein said cloth ring seal furtherincludes a shim assemblage with an outer peripheral portion opposing aninner peripheral portion of said cloth assemblage, said shim assemblageincluding a plurality of planar shim strips welded together and anarcuate shim portion, said arcuate shim portion having a first endwelded to a first planar shim strip and a second end coupled to a secondplanar shim strip, wherein said arcuate shim portion and said planarshims strips form a closed loop.
 13. The seal assembly according toclaim 12, wherein said second mating body comprises a portion of a fuelnozzle.
 14. The seal assembly according to claim 12, wherein a densityof said cloth ring seal is selected to control the rate of flow of a gasthrough said cloth ring seal.
 15. The seal assembly according to claim12, wherein said cloth ring seal includes a cavity disposed therein. 16.The seal assembly according to claim 15, wherein said shim assemblage isinterposed between said cavity and said cloth assemblage.
 17. The sealassembly according to claim 12, wherein said cloth and said shimassemblage are tubular.
 18. The seal assembly according to claim 12,wherein said cloth assemblage includes a plurality of planar clothstrips coupled together.
 19. The seal assembly according to claim 12,wherein said cloth assemblage is adapted to permit a flow of fluidthrough said cloth ring seal from a first region of said tubular cavityto a second region of said tubular cavity.
 20. The seal assemblyaccording to claim 19, herein said fluid comprises a gas.
 21. The sealassembly according to claim 12, wherein said first mating body comprisesa cap assembly and second mating body comprises a fuel nozzle of a gasturbine engine.
 22. The seal assembly according to claim 12, whereinsaid second mating body is rotatable within the cloth ring seal.
 23. Agas turbine engine, comprising: a cloth ring seal adapted to seal atubular cavity between a first mating body and a second mating body,said cloth ring seal having an inner circumferential portion adapted tomake sealing contact with the second mating body, said cloth ring sealfurther including a cloth assemblage; wherein said cloth ring sealfurther includes a shim assemblage with an outer peripheral portionopposing an inner peripheral portion of said cloth assemblage, said shimassemblage including a plurality of planar shim strips welded togetherand an arcuate shim portion, said arcuate shim portion having a firstend welded to a first planar shim strip and a second end coupled to asecond planar shim strip, wherein said arcuate shim portion and saidplanar shims strips form a closed loop.
 24. The gas turbine engineaccording to claim 23, wherein said cloth assemblage is adapted topermit a flow of fluid through said cloth ring seal from a first regionof said tubular cavity to a second region of said tubular cavity. 25.The gas turbine engine according to claim 24, wherein said fluidcomprises a gas.
 26. The gas turbine engine according to claim 23,wherein said first region comprises a combustion region and the secondregion comprises a premixing region.
 27. The gas turbine engineaccording to claim 23, wherein said first mating body comprises a capassembly and second mating body comprises a fuel nozzle.